Rx7supra

I looked under car, (has no power. slow revs) and my catylac converters were bright red... could this cause my problems? i mean it has no power, wont idle, revs slow, wants to die.

NZConvertible

Hell yeah! That thing's stuffed. Rip it out and replace it with an aftermarket one (you'll get your power back) or a piece of pipe (you'll get even more power!).

ka8legend

Yeah mine was clogged so I punched out both the main & precats. Don't see why members say it's bad for air flow, didn't seem to kill power at all as compared to my 87 na with race pipe & rb presilencer.

NZConvertible

Unless you have properly tuned extractors (meaning the rest of the exhaust does not need to provide any backpressure), it won't make as much difference on a NA as it will on a turbo, which respond better to reduced backpressure.

Jerk_Racer

Gutting the cats is a band-aid quick fix. You should get a downpipe, "test pipe" (unless you have emission testing in your area), and cat-back. Stock exhausts with gutted cats still are just that, stock. Brand new cats from the factory flow very well. Without the cats in there will be plenty of turbulence. This adds backpressure. If your cat housing were anything like mine you'll also get plenty of backfiring. It's cool at first, but it'll eventually ruin your exhaust. Just look at mine in the attached picture. If you can see it, let me know.

jerk_racer@hotmail.com

ka8legend

So the muffler blew up because the gutted cat made the car run rich and throw flames? Wouldn't a straight pipe/presilencer have the same effect then?

Jerk_Racer

I'm guessing that there was a huge pressure surge everytime it backfired. The canister was the weak link that day. Now that I have a 3" straight through exhaust, I can barely tell when it flames. My buddy had to tell me that it was doing it.

jerk_racer@hotmail.com

vaughnc